In certain cases yes
A person, no, but this question is about human life which we kill all the time, when you amputate a limb you kill billions of living human cells yet this is considered moral by the majority of the population.
Yes, it is moral to assist a chronically ill,severely suffering human to die when there is no treatment or cure in sight for many years. It is unethical to allow long term sufdering as we do now. Obviously, human euthanasia would have to have stringent regulations , guidelines, criteria. And a human euthanasia protocol program would need to be ran and overseen by a very ethical, moral body . ThTherefore this excludes the government, most western medicine physicians, and especially insurance companies.
Sure if they want to be euthanized.
No, it's not moral. It may be necessary so that the majority may live, but we shouldn't kid ourselves if we do take an innocent person's life. We can commit evil. We can fall. That's life. We can also atone though. We can strive to redeem ourselves. If morality was that flexible, we'd be lost trying to justify our actions instead of atoning with full knowledge that we strayed from the path.
I am just wondering what the response would be if innocent isn't mentioned in the question.